Video hosting websites typically maintain a repository of videos and provide a front end user interface that allows users to browse, search, and watch videos. Some video hosting websites produce original video content. Other video hosting websites license video content from third parties. Other video hosting websites allow users to upload videos and share those videos with the public at large or with one or more other users who are granted access to the videos.
User interfaces for browsing or searching videos often display results in the form of thumbnails corresponding to videos. The thumbnails typically represent a single frame of the video. As an example, a video may be encoded at a frame rate of 30 frames per second. In the context of a lengthy video, a single frame may or may not convey meaningful information to a user that is browsing or searching a large library of videos. Sometimes, text descriptions of videos are displayed to supplement single-frame thumbnails. In some instances, the text descriptions can be missing, incomplete, or inaccurate. As a result, it may be difficult for a user to quickly understand the nature of the content that is presented in a video or a group of videos.
The video repositories that are maintained by video hosting sites can become very large. For this reason, video search engines have been developed to allow users to search for videos. Some video search engines utilize data regarding the popularity of a video as one basis for ranking and sorting videos within search results. This can bias video search results in favor of older content.